Study type: Medical/biological study (experimental study)

Influence of pulsed electromagnetic field with different pulse duty cycles on neurite outgrowth in PC12 rat pheochromocytoma cells. med./bio.

Published in: Bioelectromagnetics 2005; 26 (5): 406-411

Aim of study (acc. to author)

To study the influence of the pulsed electromagnetic field with different pulse duty cycles on neurite outgrowth in PC12 cells (these cells can react to the addition of the nerve growth factor by differentiating and growing neurites).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Modulation type: pulsed
Exposure duration: continuous for 96 h
10% pulse duty
Exposure 2: 50 Hz
Modulation type: pulsed
Exposure duration: continuous for 96 h
30% pulse duty
Exposure 3: 50 Hz
Modulation type: pulsed
Exposure duration: continuous for 96 h
50% pulse duty
Exposure 4: 50 Hz
Modulation type: pulsed
Exposure duration: continuous for 96 h
80% pulse duty
Exposure 5:
Exposure duration: continuous for 96 h
DC field (100% pulse duty)
Exposure 6:
Exposure duration: continuous for 96 h
DC field (100% pulse duty)

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 96 h
Additional info 10% pulse duty
Modulation
Modulation type pulsed
Rise time 2 ms
Fall time 2 ms
Additional info

Rectangular pulses with 10 % duty cycle

Exposure setup
Exposure source
Chamber 5% CO2 incubator maintained at 37°C
Setup 3 Dishes were placed horizontally, centered between the two coils within the incubator. The magnetic field was parallel to the surface of the medium.
Additional info The coils were mounted coaxially and were 13 cm apart. identical control dishes were kept in an second identical incubator without electromagnetic field for the same amount time.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.36 mT peak value measured - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 96 h
Additional info 30% pulse duty
Modulation
Modulation type pulsed
Rise time 2 ms
Fall time 2 ms
Additional info

Rectangular pulses with 30 % duty cycle

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.36 mT peak value measured - -

Exposure 3

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 96 h
Additional info 50% pulse duty
Modulation
Modulation type pulsed
Rise time 2 ms
Fall time 2 ms
Additional info

Rectangular pulses with 50 % duty cycle

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.36 mT peak value measured - -

Exposure 4

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 96 h
Additional info 80% pulse duty
Modulation
Modulation type pulsed
Rise time 2 ms
Fall time 2 ms
Additional info

Rectangular pulses with 80 % duty cycle

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.36 mT peak value measured - -

Exposure 5

Main characteristics
Frequency
Type
Exposure duration continuous for 96 h
Additional info DC field (100% pulse duty)
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.36 mT - measured - -

Exposure 6

Main characteristics
Frequency
Type
Exposure duration continuous for 96 h
Additional info DC field (100% pulse duty)
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT - measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The pulse duty cycle had significant effect on neurite outgrowth. Low (10%) pulse on-time significantly inhibited the percentage of neurite bearing cells. At the same time it increased the average length of neurites, while 100% on-time had exactly the opposite effects. Furthermore, the authors found that neurites were prone to extend along the direction of pulsed electromagnetic fields with 10% pulse on-time.
The studies show that neurite outgrowth in PC12 cells is sensitive to the pulse duty and this sensitivity was associated with nerve growth factor (NGF) concentration.

Study character:

Study funded by

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